[Xen-devel] [RFC PATCH v1 08/21] ARM: NUMA: Parse NUMA distance information

[vijay.kilari@xxxxxxxxx]

From: Vijaya Kumar K <Vijaya.Kumar@xxxxxxxxxx>

Parse distance-matrix and fetch node distance information.
Store distance information in node_distance[].

Signed-off-by: Vijaya Kumar K <Vijaya.Kumar@xxxxxxxxxx>
---
 xen/arch/arm/dt_numa.c     | 90 ++++++++++++++++++++++++++++++++++++++++++++++
 xen/arch/arm/numa.c        | 19 +++++++++-
 xen/include/asm-arm/numa.h |  1 +
 3 files changed, 109 insertions(+), 1 deletion(-)

diff --git a/xen/arch/arm/dt_numa.c b/xen/arch/arm/dt_numa.c
index fce9e67..8979612 100644
--- a/xen/arch/arm/dt_numa.c
+++ b/xen/arch/arm/dt_numa.c
@@ -28,6 +28,19 @@
 
 nodemask_t numa_nodes_parsed;
 extern struct node node_memblk_range[NR_NODE_MEMBLKS];
+extern int _node_distance[MAX_NUMNODES * 2];
+extern int *node_distance;
+
+static int numa_set_distance(u32 nodea, u32 nodeb, u32 distance)
+{
+   if ( nodea >= MAX_NUMNODES || nodeb >= MAX_NUMNODES )
+       return -EINVAL;
+
+   _node_distance[(nodea * MAX_NUMNODES) + nodeb] = distance;
+   node_distance = &_node_distance[0];
+
+   return 0;
+}
 
 /*
  * Even though we connect cpus to numa domains later in SMP
@@ -112,6 +125,66 @@ static int __init dt_numa_process_memory_node(const void 
*fdt, int node,
     return 0;
 }
 
+static int __init dt_numa_parse_distance_map(const void *fdt, int node,
+                                             const char *name,
+                                             u32 address_cells,
+                                             u32 size_cells)
+{
+    const struct fdt_property *prop;
+    const __be32 *matrix;
+    int entry_count, len, i;
+
+    printk(XENLOG_INFO "NUMA: parsing numa-distance-map\n");
+
+    prop = fdt_get_property(fdt, node, "distance-matrix", &len);
+    if ( !prop )
+    {
+        printk(XENLOG_WARNING
+               "NUMA: No distance-matrix property in distance-map\n");
+
+        return -EINVAL;
+    }
+
+    if ( len % sizeof(u32) != 0 )
+    {
+         printk(XENLOG_WARNING
+                "distance-matrix in node is not a multiple of u32\n");
+
+        return -EINVAL;
+    }
+
+    entry_count = len / sizeof(u32);
+    if ( entry_count <= 0 )
+    {
+        printk(XENLOG_WARNING "NUMA: Invalid distance-matrix\n");
+
+        return -EINVAL;
+    }
+
+    matrix = (const __be32 *)prop->data;
+    for ( i = 0; i + 2 < entry_count; i += 3 )
+    {
+        u32 nodea, nodeb, distance;
+
+        nodea = dt_read_number(matrix, 1);
+        matrix++;
+        nodeb = dt_read_number(matrix, 1);
+        matrix++;
+        distance = dt_read_number(matrix, 1);
+        matrix++;
+
+        numa_set_distance(nodea, nodeb, distance);
+        printk(XENLOG_INFO "NUMA:  distance[node%d -> node%d] = %d\n",
+               nodea, nodeb, distance);
+
+        /* Set default distance of node B->A same as A->B */
+        if ( nodeb > nodea )
+            numa_set_distance(nodeb, nodea, distance);
+    }
+
+    return 0;
+}
+
 static int __init dt_numa_scan_cpu_node(const void *fdt, int node,
                                         const char *name, int depth,
                                         u32 address_cells, u32 size_cells,
@@ -136,6 +209,18 @@ static int __init dt_numa_scan_memory_node(const void 
*fdt, int node,
     return 0;
 }
 
+static int __init dt_numa_scan_distance_node(const void *fdt, int node,
+                                             const char *name, int depth,
+                                             u32 address_cells, u32 size_cells,
+                                             void *data)
+{
+    if ( device_tree_node_matches(fdt, node, "distance-map") )
+        return dt_numa_parse_distance_map(fdt, node, name, address_cells,
+                                          size_cells);
+
+    return 0;
+}
+
 int __init dt_numa_init(void)
 {
     int ret;
@@ -149,6 +234,11 @@ int __init dt_numa_init(void)
 
     ret = device_tree_for_each_node((void *)device_tree_flattened,
                                     dt_numa_scan_memory_node, NULL);
+    if ( ret )
+        return ret;
+
+    ret = device_tree_for_each_node((void *)device_tree_flattened,
+                                    dt_numa_scan_distance_node, NULL);
 
     return ret;
 }
diff --git a/xen/arch/arm/numa.c b/xen/arch/arm/numa.c
index 9a7f0bb..11d100b 100644
--- a/xen/arch/arm/numa.c
+++ b/xen/arch/arm/numa.c
@@ -22,14 +22,31 @@
 #include <asm/mm.h>
 #include <xen/numa.h>
 #include <asm/acpi.h>
+#include <xen/errno.h>
+
+int _node_distance[MAX_NUMNODES * 2];
+int *node_distance;
+
+u8 __node_distance(nodeid_t a, nodeid_t b)
+{
+    if ( !node_distance )
+        return a == b ? 10 : 20;
+
+    return _node_distance[a * MAX_NUMNODES + b];
+}
+
+EXPORT_SYMBOL(__node_distance);
 
 int __init numa_init(void)
 {
-    int ret = 0;
+    int i, ret = 0;
 
     if ( numa_off )
         goto no_numa;
 
+    for ( i = 0; i < MAX_NUMNODES * 2; i++ )
+        _node_distance[i] = 0;
+
     ret = dt_numa_init();
 
 no_numa:
diff --git a/xen/include/asm-arm/numa.h b/xen/include/asm-arm/numa.h
index cdfeecd..b8857e2 100644
--- a/xen/include/asm-arm/numa.h
+++ b/xen/include/asm-arm/numa.h
@@ -11,6 +11,7 @@ typedef u8 nodeid_t;
 int arch_numa_setup(char *opt);
 int __init numa_init(void);
 int __init dt_numa_init(void);
+u8 __node_distance(nodeid_t a, nodeid_t b);
 #else
 static inline int arch_numa_setup(char *opt)
 {
-- 
2.7.4


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